Helicopter



Dec. 27, 1932.

D. R. CAMPENS KELICOPTER Filed Marblg s, 1952 5 Sheets-Sheet 1 i was we a;

Dec. 27,1932. D. R. CAMPENS HELICOPTER Filed March 3, 1932 5 Sheets-Sheet, 2

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Dec. 27, 1932. D. R. CAMPENS HELICOPTER 5 Sheets-Sheet 5 Filed March 3, 1932 Dec. 27, 1932. D. R. CAMPENS 1,892,036

HELICOPTER Filed March 5, 1932 5 Sheets-Sheet 5 Patented Dec. 27, 1932 PATENT OFFICE- DENIS REMY CAMPENS, OF B EBCHm-ANTWERP, BEIGIUM nmcorran Application filed March a, 1932, Serial no. 596,527, aud in Belgium April 17, 1931.

The present invention relates to the im- I proved construction of helicopters, i. e. aviation apparatus heavier than air, ca able of leaving a spot on the ground solely y their own means on board, to rise in the atmos-- phere and return to the same spot on the ground, all these movements being performed on a vertical line passing through the said spot. i

In order to give a more practical character to the apparatus, it is desirable to add toithe same certain devices enablingit to .perform movements according to the three dimensions of space. The great difiiculty presented in embodying ahehcopter is its stability. Consequently, the greatest care'is required in order to obtain good stability as wellin the shape as in governing.

The invention will be described hereafter with reference to the accompanying drawings, in which different forms of embodiment have been illustrated.

Figs. 1, 2 and 3 arerespectively a plan view, a front View and a side view of a helicopter in accordance with the invention;

Figs. 4' and 5 are a partial plan view. and a partial side elevation showing details of the apparatus;

Figs. 6, 7 and 8 are front elevations of further forms of embodiment of a helicopter;

Figs. 9, 11, 12, 13 and 14 refer to calcula tions cited in the description;

Fig. 10 is a partial plan view of a lifting propeller used with the helicopter; v

Fig. 15 shows a 'diagrammatlc composition of driving and clutching means securing stability in the longitudinal direction;

Figs. 16 to 20 illustrate diagrammatically some details of the mechanisms used in the apparatus; I

Figs. 21 and 22 illustrate respectively-a front elevation and a lan view of a further improved form of em odiment of the heli- 4 copter; Fig. 23 is a diagrammatic composition of driving and clutching elements used for securing longitudinal stability.

With reference to the drawings, the heli-' copter has a cross-shaped fuselage 1, 2, 3, 4, constituted with trellis-work girders. At

rudder 33.

each end 3 and 4 are mounted balancing I frames 5 and 6. These frames are capable o oscillating in transverse direction about their horizontal axis, between the front and rear end plates of the girder 3-4. Two connecting rods 7 v and 8 each join the upper edge of one of the balancin frames 5 to the lower edge of the opposite alancing frame 6. Each balancing frame carries in its lower part a star-shaped air-cooled motor 9 and 10, the 2 vertical shafts of which are extended upwards and on which are mounted the horizontal lifting propellers 11 and 12, rotating in opposite directions the one to the other.

Close above each motor 9 and 10 and on their extended axles, are keyed small fans ensurin the cooling of the motors. The motor sha s 13 and 14 are also extended downwards and engage with bevel gear boxes 15' and 16, from which the shafts protrude again and carry at their lower ends horizontal flywheels 17 and 18, the latter rotating in opposite direction to the coupled lifting propellers, thus absorbing the gyroscopic efforts.

Each balancing frame carrles at itslower end a wheel 19 and 20, provided with a shock-absorber 21 and 22. At the front end of the girder .1-2 is fixed the driving motor On the front shaft of the motor 23 is keyed a tractor propeller 24 preferably with four blades. p

A horizontal propeller 25 is mounted at the rear of the pilots seat 26. The front and rear ends of thecross-shaped fuselage are also provided with a wheel 27 and 28 and a shockabsorber 29 and 30..

The balancing frames can, by means of a set of levers and rods be wedged at on the cross-shaped fuselage. e

For the purpose of clearness of Figs. 1, 2 and 3, the additional Figures 4 and 5 show the-disposition of the lateral ailerons 31, of the horizontal rudder 32 and of the vertical In the embodiment illustrated in Fig. 6, the motor frames are fixed and converge to one another in the upward direction The lifting propellers will thus maintain the front of the transverse straight girder. Themotor power is transmitted to the lifting propellersby means of geared bevel-wheels 35,

1 and 36. For cleai'ness of the drawing, the

motor and the front propeller are not shown. In Fig. 8, which is the same as Fig. 7, the transverse girder is not straight but formed with two parts inclined to each other in the upward direction. This model gives the-best working solution and a preferred form of construction is further illustrated in Figs. 21 and 22. r v

The advantage secured by constructions according to Figs. 1 to 3, consists in the fact that the lifting propellers take a variable balanced position at each moment, due to the variation, intentional, or accidental, of the center of pression of each lifting propeller. On the other hand, the apparatus according to the alternative forms is of a stronger construction, less heavy, gives less vibrations and is submitted to less harmful efforts, is less subjected to gyroscopic effects and can admit a greater horizontal translation; ow-.

ing to this fact, it will be more practical, more sure andeasier to control.

The ailerons will only be used for horizontal flight, together or not with the liftin'g balancing propellers. The horizontal rudder is also employed only for horizontal motion.

The profile, the pitch, the shape, the dimensions, the number and kind of coupling of the blades forming the lifting propellers are all factors-influencing the aerodynamic eflicien 'of the apparatus.

The "fting propellers for an apparatus operating at a fixed spot or in simple vertical translation, and the lifting propellers for an apparatus-capable of moving according to the three dimensions of space will not be thesame. i f 5 I In the first case, the lifting propellers Wlll only be submitted to one velocity: the rotation speed (theapparatus being in free space with no or nearly'no wind in comparison with the rotation speed), and in the second case,- the" horizontal translation velocity, which is added and may attain appreciable values comparison with the rotation speed; by this fact, the conditions of the lifting propellers are changed from one case to the other.- i

In the. case of the lifting propellers in a simple vertical translation, the best raising qualities correspond to variable inclinations of each blade and this from the center (motor shaft) until the periphery, because the speed of each blade varies'from 0 in the center to 2114- 1 at the periphery. The angle fix ing the inclination angle of a lifting propeller in vertical translation is given by the an- Now, in the center V =0 resulting in resulting in a 90 at the periphery V =21rm resulting in Thus in this case the-lifting propeller will be at.90 near the vertical root and reduce progressively until the periphery, where it approaches 0, thus nearly horizontal.

By a lifting propeller in horizontal translation, these conditions change, because horizontal speed intervenes and must be taken into account. I r

In this case, analogous to the one of a fixed aeroplane wing, a uniform angle near to 10 is required along the whole length of the blades, so as to obtain a maximum thrust with a minimum trail.

A right intermediate choice must be taken between these two solutions. The blades of the lifting propellers approaching the shape of driving propellers of an aeroplane, give a good solution. Being intended for rotating at high speeds and in order to neutralize by this fact effects of centrifugal force, the blades will preferably be made of one single piece of wood or light metal.

The velocity of the blades along their longitudinal axis varies, as explained above, froma minimum 0 at the root, to a maximum 21rrn in the periphery. In consequence, the

maximum value-of the thrust K SV dS theoretically situated at the periphery. Practically, this maximum value is found to the rear at about of the length of the blades at their root. Therefore, it is advantageous to give to this part of the lifting propeller greater surface, so as to obtain a maximum thrust for a given lifting surface. The tips near the periphery will be rounded and cut away, in order to reduce at the rear edge of the eddy currents harmful to the good aero dynamic eiiiciency of the blades. The inclination of the blades on the horizontal line will be nearly constant along their whole length. As in the case of an aeroplane wing, the elongation must also be taken into account. A great elongation gives the best results; unfortunately,this would lead us to blades of too great a diameter, which would conse quently, at great speeds, undergo too heavy a strain. Au elongation from four to five times is to be recommended.

. As a result of all these considerations, the

blades of a helicopter made to move according to the three dimensions of space will have a similar shape to the one of Fig. 10.

The quantity of blades per lifting propeller as well as the coupling system-of same play an important part in the aerodynamic efficiency of the planes. The best solution for a helicopter intended for simple vertical translation is a lifting propeller with two blades, giving the least interaction, but the lifting propeller with 'four blades gives more stability, a better distribution of the load per area unit'and planes of less-diameter.

Every helicopterniust at least have two lifting propellers rotating in opposite directionsthe one to the other, in such a way that the reaction torques will bevmutually neutralized, or else an additional device repudiating the torque. Without such device, the apparatus would turn round itself, The two lifting propellers rotating in opposite directions may be on concentric shafts or side by side. Although con-,

centric lifting. propellers'give less volume to the apparatus, the system side by side is preferred, as it causes less interactions and gives in consequence superior raising quality.

-would be obtained atthis side.

Witlr relation to lateral stability, the lifting propellers aotboth as lifting devices and lateral balancers. v 1

Lateral stabilizing is obtained, bycoupling a separate motor to each lifting propeller, with separate working. e

.In this way, when one of the lifting propellers lowers or rises, and by this fact inclines the apparatus in lateral direction, the

rotation velocity of the motor coupled to the lifting propeller-in question will be increased or decreased, in such a way as to raise. or reduce the thrust. Each lifting propeller operateslevers of nearly equal len h, but the one operating with greater force rings back the a paratus to its horizontal position. As the t nets are equal to K SV and K S being nearly identical for both lifting propellers, when doubling the speed of one of the motors, a thrust which is four times greater In simple vertical translation with horizontal wind and in horizontal translation (results are nearly the same) the relative velocity of each blade of a lifting propeller differs periodically at every revolution, as is shown in Figs. 11 and 12, in which:

in point C='V12 I in point E /V +o +2l o cos B in point F= {Wan -2V2; cos ,3 thus with a maximum in A with V+v and a minimum in C with V'v. The centers of pressure are consequently eccentered and do not correspond to the center 0 of the lifting propeller (Fig. 13).

For A and C' the center of pressure will be in G.

For D and B, being alike, it will be in the center 0.

For E and F, in the point H.

Thus in one complete rotation the center of pressure will have made a circumference with diameter DVv T V v5 D=diameter of the lifting propeller.

For two lifting propellers coupled side by side, rotating at a uniform speed and in horizontal translation the general resultant for a pressure of the two lifting propellers will pass along the symmetry line of the mo apparatus (vertical line passing through the center of symmetry).

If intentionally or accidentally the 'rotation speed of one of the lifting propellers is changed and does not correspond anylonger to the other, the resulting force will no longer pass along the symmetry center and the apparatus will ,incline to the side of less speed. In Fig. 14 comparison is made in case of accidental decrease of speed or pressure of one (dotted lines) i 1 1 d t 1 I a n5 p=ve 0c tyinacci ena decrease 1 p =unchanged velocity Apparatus with p'-=balanclng velocity P =reqult straight axes. p velocity in intentional 1 l i f l id t l p=veoc ,vnacc ela ecrease k p ==unchanged ve1oc1ty Apparatus with p=ba1ancing velocity P =res-u1t converging axes. .p=velocity in intentional ant decrease 1 as stated above.

The combined action of pressure increase on the plunging s1de (intentional mcrease of the rotation speed of the plunging motor) :with straight axes, the same tends to remain longer inclined and even to permit to the apparatus to start an oblique lateral gliding flight.

When the apparatus puts itself laterally oblique it will tend to start a gliding flight in the direction of inclination.

The apparatus with converging axes has the great advantage to prevent or at least to absorb or retard this gliding flight, thanks to its great stability of shape, due to the converging of its motor shafts. The plunging lifting propeller receives in fact a higher thrust'than the other and tends to right the apparatus automatically.

Thus in case of lateral inclination, thesis different factors decreasing its motion will permit the pilot to operate in due time the plunging motor, so as to increase its speed and at the same time decrease the speed of the rising motor, so as to bring back the apparatus to its horizontal position.

The gliding flights will equally beabsorbed by the'great inertia possessed by the apparatus itself.

In horizontal motion, longitudinal balance can be obtained by the action exerted by the rear horizontal plane 32, Fig. 4.

In simple vertical translation, this stability is secured by a horizontal propeller operated (for the' sake of weight economy) by the front tractor motor. By means of a lever and sliding change speed pinions, this propeller can rotate either in one or in the other direction, causing in this way either an upward thrust or a downward thrust, ac-

cording to the direction of rotation.

The front driving propeller 24 (Fig. 15) is coupled by its shaft to the motor 23, by means of a usual clutch system 37. The motor shaft carries at its rear end a gear-wheel 38 permanently meshing with another wheel 39 keyed on shaft 40. This shaft 40 carries 4 also two other gear-wheels 41 and 42. The

wheel 42 meshespermanently'with wheel 43 keyed on shaft 44. The lever 45 pivoting about a point 46- is provided'with a latch.

spring lever 47, which can be stopped at a notch of a toothed sector 48. The operating of the lever either to thefront or to the rear (direction of arrows 49 and 50) draws with it two'rods 51 and the sleeve 52 with guide slot (sliding on shaft 53). On the sleeve 52 are keyed two gear-wheels 54 and 55. The lever 45 slides and draws with it the sleeve 52 by means of asecond concentric guided sleeve 56, between two abutments 57 (for details see Fig. 16) and can place either the wheel 54 and 41 or 55 and 43 in front to one another. The shaft 53 transmits the motor movement to a bevel gear 58 and 59, the latter transmitting the rotation to a horizontal propeller 25 keyed on shaft 60.

The two rods 51 transmit a to and fro movement to two parts 61 covered with asbestos and used as a brake (Prony type) on shaft 60, at each change of rotation of this shaft (for details see Fig. 17).

At each change of direction of rotation of the horizontal propeller, the motor shaft is uncoupled from the motor by means of an uncoupling system 62. The uncoupling movement is transmitted by the lever 45 to a plunger 63 acting on the retaining spring of the clutch (not shown in the figure so as not to interfere with the clearness of the drawing) by means ofthe rod 64, the crank lever 65, the rod 66 and the slide block 67.

The movement of the slideblock is adjusted insuch a way that the wheel 54 or 55 is already slightly meshing with respectively the wheel 41 or 43 before the clutch 62 has i worked, and reciprocally by uncoupling.

Beside the usual instruments as altimeter,

revolution indicator, etc., the steering cabin contains:

( 1) a starting lever for each motor (thus Y rudder and the planes; Q

(4) a rocking lever operating the rudder;

(5) a keying lever for the balancing frame;

(6) a steering lever for the longitudinal lifting propeller;

(7) a lever forcoupling and uncoupling the I front driving propeller.

The steering 5 is only used in certain cases,

such as free fall, etc., for an apparatus with moving balancing frames.

With reference to the' automatic coupling and uncoupling of the lifting propellers (Figs. 18 to 20), each lifting propeller turnsloose on its shaft 68, by means of a ball bearing 69 between them. Each lifting propeller is provided at its lower base with a coaxial cup 70, fixed to thelifting propeller and which ends beneath in a straight gearing crown 71 .with deep recesses. Thejoining of' the cup with the lifting propellers will be made by means of a spring between them, so as to absorb the shock at the moment of coupling the.

planes.

Beneath the cup, the motor shaft carries the lifting propeller in the rotation move-' ment of the motor shaft (Figs. 19 and 20).

This device permits:

(1) to descend in free fall, the lifting mo tors stopped. The apparatus descends as a parachute, the lifting propellers rotating freely on their shaft with a speed which accelerates with acceleration of the falling the thrust is increased and falling speed by this fact is decreased (lifting propellers .un-

coupled) (2) to fly with autorotation;

(3) to fly in horizontal translation with the front driving motor stopped and lifting propellers coupled. In fact, when inclining the apparatus rearwards and forming an oblique with the horizontal line, the horizontal composing force of the reaction on the lifting propeller producesforward drive.

= The obliquity is obtained in this way through the horizontal rudder.

The following operations are to be done in case of break down of one or more of the motors: v

1) Break down of the front driving motor: v I

Flight may be continued in horizontal translation by flying with the apparatus in 40 obli uity to the horizontal.

(2 Breakdown of lifting motors:

Flight may be continued in autorotation.

(3) Break down of the three motors:

Descent may be done:

0 3a either in oblique, while steering to fixed spot, in autorotation, due to the acquired gliding flight speed;

3?) or else along avertical line, the apparatus falling as a parachute.

A further form of embodiment of the heli-' copter has been illustrated in Figs. 21 and 22. The helicopter being intended for moving in vertical and horizontal directions, will have the most advantageous profile when the general shape of the apparatus will be that of a convexo-convex lenticular figure, this shape giving the least resistance with respect to the directions of movement referred to hereabove.

An apparatus of this shape will have lifting propellers 75, a vertical rudder 7 6,-air-cooled motors with fans 77 for driving the lifting propellers, tractor ropellers 78, ailerons 79, bevel gear transmissmns 80 for the lifting propellers, a motor 81 for the tractor propellers,

speed. By acceleration of the rotation speed bevel gear transmissions 82 for the tractor propellers 78, seats 83 for the pilot -and conveyor, a horizontal rudder 8 l, stabilizing propellers 85 at the end of the fuselage, one above and the other underneath the rudders, said stabilizing propellers being adapted to move in opposite directions. Fuel and oil will be advantageously stored in the tank 86.

The three motors for this apparatus will be of light construction.

The lifting propellers will be made for instance from multiple layer wood or from a resistant and light metal. These lifting propellers will be constructed similar to the tractor propellers, the pitch being variable and having an angle of a: 0. Otherwise the inclination of the blades can be uniform or constant from the center to the periphery. Automatic clutch devices can be provided for driving the propellers. l

This aeroplane can be provided with one or two tractor propellers in front of and under neath the lifting propellers. When moving in vertical direction, the ailerons and horizontal rudder can be placed in a vertical plane, in order to reduce resistance of the atmosphere.

Longitudinal stability during vertical flight is secured by means of two separate propellers similar to the lifting propellers, but

of reduced dimensions, the one being arranged abovethe fuselage and the other underneath, close to the rudders. These stabilizing propellers are separately controlled by means of a lever and can rotate in opposite directions so that, as a technical effect, one of these propellers will lift 'the fuselage and the other draw it downwards.

The controlling device as illustrated in Fig. 23 comprises: a driving shaft 87 from the front tractor motor, gear transmissions 88 and 89, clutches 90 for the stabilizing propellers, the controlling lever 91 for said clutches 90, the lever moving along a'toothed sector 92, friction brakes 93, movable elements 94 cooperating with said brakes, bevel gears 95 for driving the stabilizing propellers 96 and 97 The tractor propeller can be unclutched.

I claim:

1. A helicopter comprising in combination a cross-shaped fuselage, an oscillating frame on each side of the fuselage arranged at each endof the transverse cross member, the oscillation axis of said frames being substantiaL' 1y horizontal and parallel to the longitudinal cross member, a lifting propeller at the top side of each oscillating frame, a .sepa rate motor in each oscillating frame for driving the lifting propeller, a fly-wheel in each oscillating frame driven by said motor, a tractor propeller at the front end of the longitudinal cross member, a motor driving the tractor propeller, ailerons underneath the transverse cross member, a horizontal and a vertical rudder, a stabilizing propeller at the rear end of the longitudinal cross member, means to drive the last-mentioned stabilizing propeller, a landing structure comprising wheels and shock-absorbing devices, automatic coupling system of the two lifting propellers, and means to control the operation of the lifting, stabilizing and tractor propellers, submotor for driving each lifting propeller and located at each lateral cross end structure, a tractor propeller at the front end of the longitudinal cross member, a. motor driving the tractor propeller, ailerons underneath the transverse cross member, a horizontal and a vertical rudder, a stabilizing propeller at the rear end of the longitudinal cross member,

1 means to drive the last-mentioned stabilizing propeller, a landing structure comprising wheels and shock-absorbing devices, automatic coupling system of the two lifting propellers, and means to control the operation of the lifting, stabilizing and tractor propellers, substantially as set forth.

3. A helicopter comprising in combination: a cross-shaped fuselage, a fixed frame on each side of the fuselage and arranged at each end of the transverse cross member, contained in an oblique plane to the horizontal plane of the longitudinal cross member forming a V-shaped construction, a lifting propeller mounted at the top side of each lateral' cross end structure, the ,shafts of said lifting propellers beinginclined to each other in an upward and converging direction, a separate motor for driving each lifting propeller land located at each lateralcross end structure, a tractor propeller at the front end of the longitudinal cross -member, a motor driving the tractor propeller, ailerons underneath the transverse cross member, a horia cross-shaped fuselage, a fixed frame on each side of the fuselage and arranged at each end of the transverse cross member, contained in an oblique plane to the horizontal plane of the longitudinal cross member forming a V- shaped structure, a lifting propeller mounted at the top side of each lateral cross end structure, the shafts of said lifting propellers being inclined to each other in an upward and converging direction, a separate motor for driving each lifting propeller and located in the centre of the cross-shaped fuselage, transmission gears for driving the lifting propellers, by said motors, a tractor propeller at the front end of the longitudinal cross member, a motor driving the tractor propeller, ailerons underneath the transverse cross member,

a horizontal and a vertical rudder, a stabilizing propeller at the rear end of the longitudinal cross member, means to drive the lastmentioned stabilizing propeller, a landing structure comprising wheels and shock-absorbing devices, automatic coupling system of the two lifting propellers, and means to control the operation of the lifting stabilizing and tractor propellers, substantially as set forth.

5. A helicopter comprising in combination: a cross-shaped'fuselage, a fixed frame on each side of the fuselage and arranged at each end of the transverse cross member, contained in an oblique plane to the horizontal plane of the longitudinal cross member forming a V-shaped structure, a lifting propeller mounted at the top side of each lateral cross end structure, the shafts of said lifting propellers beingv inclined to each other in an upward and converging direction, a separate motor for driving each lifting propeller and located in the centre of the cross-shaped'fuselage, transmission gears for driving the lifting propellers by said motors, a tractor propeller at the front end of the fuselage, a motor driving the tractor propeller, ailerons underneath the transverse cross member, a

horizontal and a vertical rudder, stabilizing propellers at the rear end of the longitudinal cross member, means to drive the last-mentioned stabilizing propellers, a convexo-convex lenticular fuselage, a landing structure comprising wheels and shock-absorbing devices, automatic coupling system of the lifting propellers, and means to control the ope'rat-ion of the lifting, stabilizing and tractor propellers. zontal and a vertical rudder, a stab1l1z1ng.-,.

propeller at the rear end of the longitudinal ii i name.

In testimony whereof I signed hereunto n. R. CAMPENS. 

